Draft rigging



Dec. 12, 1950 H. L. SPENCE ETAL 2,533,903

DRAFT RIGGING Filed Oct. 1a, 1946 4 Sheets-Sheet 1 INVENTORS HUBERT L. SPENCE WILLIAM L]. METZGER ATTORNEY INVENTORS HUBERT L. SPENCE WGLfL/AM J. METZGER 4 Sheets-Sheet 2 ATTORNEY Dec. 12, 1950 H. L. SPENCE ETAL DRAFT RIGGING Flled Oct 1a 1946 4 Sheets-Sheet 3 INVENTORS HUBEPT L. SPENCE WBILi LIAM d. METZ'GER ATTORNEY H. L. SPENCE ETI'AL DRAFT RIGGING Dec. 12, 1950 Filed Oct. 18, 1946 1950 H. 1.. SPENCE ETAL 2,533,903

DRAFT RIGGING Filed Oct. 18, 1946 4 Sheets-Sheet 4 i I 28 I9 m HIE NNNNNNN RS HUBERT L.5PENCE VVBI$LIAM d. METZGER ATTORN Y Patented Dec. 12, 1950 UNITED STATES PATENT OFFICE DRAFT RIGGING Application October 18, 1946, Serial No. 704,188

12 Claims.

The invention relates to friction draft gears, having particular reference to mine car applications although not restricted to this alone.

It is an object of our invention to provide a compact draft gear of high capacity in relation to its size, and which has very few parts.

A further object is to provide a draft gear which will meet the limited space requirements of mine car construction while providing effective cushioning of draft and buffing shocks.

Another, and particular, object is to provide a draft gear which dispenses entirely with the need for retaining bolts or other special parts for locking the several elements of the gear in assembled relationship for shipment and/or operation.

An additional object is to provide a draft gear having dual-function interchangeable parts whereby the same part not only can be used in alternative locations but will serve two purposes in either location, thus considerably reducing the number of different parts required.

Other objects and advantages of our invention will appear as the description proceeds.

In the drawings which illustrate a preferred embodiment of our invention:

Fig. 1 is a plan view of a draft gear constructed in accordance with the invention, illustrating its application to mine cars, and Fig. 2 is a side elevational view thereof.

Figs. 3 and 4 are detail views to enlarged scale of one of the friction shoes of the gear, Fig. 3 being a top plan view thereof (considered in its relation to the assembled draft gear) and Fig. 4 an end elevational view thereof.

Fig. 5 is an end elevational view of the follower Fig. 10 is a view similar to Fig. 9 but illustrating the position of the parts as completely assembled and compressed to the dimensions of the draft gear pocket. I

Our invention comprises in its general arrangement a friction stem H, friction shoes l2 for engagement with the friction stem, a follower wedge l3 having inclined wedge surfaces M for engagement with the friction shoes, and spring means l5 for opposing movementof the shoes along the friction stem, the friction stein having a shouldered end 16 for limiting movement of the shoes, the follower wedge having a central opening I! to clear the shouldered end of the friction stem during assembly therewith, and the follower wedge and friction shoes having coacting projections I8 and grooves l9 cooperating with the shouldered end of the friction stem to hold the follower wedge and shoes against removal.

In our preferred construction there are two sets of friction shoes for engagement with opposite ends of the friction stem, a follower wedge for engagement with each set of friction. shoes, and a compression spring I5 arranged between the two sets of friction shoes. The follower wedge adjacent the shouldered end I6 of the stem has the central opening ll referred to in the preceding paragraph and the follower wedge and friction shoes have the interlocking projections and grooves as described, these projections and grooves being arranged to permit their assembly with the friction stem when the spring is compressed and thereafter to hold them against removal from the friction stem. We prefer that the follower wedge adjacent the head 20 be of the same construction as the one which is adjacent the shouldered end I5 of the stem so that the two will be interchangeable. In this case the two sets of friction shoes likewise will be constructed in the same manner and be interchangeable. Thus the follower wedges and shoes constitute dual-function interchangeable parts whereby the same part not only can be used in alternative locations but will serve two purposes in either location, thus considerably reducing the number of different parts required. The two functions of the wedges and shoes are their coaction in creating frictional resistance to compression of the draft gear in draft and bufling, and their coaction in holding the parts of the draft gear in assembled relationship without the use of retaining bolts or other special locking parts.

The shouldered end It of the friction stem provides means for limiting movement of the shoes in one direction, and it will be observed that the follower wedge is constructed and arranged to pass over the end of the friction stem during assembly therewith. The interlocking means provided by the projections I3 of the follower wedge and the grooves IQ of the shoes hold the follower wedge in assembled relationship with the friction stem and friction shoes. The interlocking portions of the wedge and shoes are arranged at an angle to the axis of the friction stem as clearly shown in Fig. 10 for example, providing locking It surfaces on the friction shoes which, in the assembled position of the friction stem, wedge and shoes, engage portions of the follower wedge to hold it against removal.

The coacting projections and grooves [8, I9 are constructed .and arranged to slide into engage ment as *tliezzfcliower ZWBdge is passed over the end of the friction stem as indicated in Fig. 9, and as will be described in greater detail hereinbelow.

Referring now more particularly to Fig 1,; we have shown in dot-dash outline a draft gear pocket including the front draftflags?! andireaz" draft lugs 22 against which/,thelends" ofithegear abut. constructed and arranged for attachment to a coupler shank as by means of the projections 23, 24 through which a vertical coupling pin. 25. extends. Portions of the coupler shank (not shown), extendbetween projections 23 and M 'for'iengagement by the "coupling'pin 25.

iIn the preferred. construction. l illustrated; the friction stem I I .and "the shouldered" end 16 thereof are generally "circular? intsh'ape. The ends .of the stem are slightlytapered asshown in 'Fig: 7'; .the stem'being somewhat "wider "at "the 'cntrith'an at its ends. .Each of the friction surfaces 25 is cylindrical'in form with the axis 'ofjtheicylinder slightly inclined "to the "longitin ,dihal ,icenterline ofthe friction stem. 'TThe ffriction shoes 12 areformedwith concave ltylindrfica1 1 surfaces, 2! corresponding" in "shape with ;.the rconvex friction surfaces .i 2.5 ofthe stem, "and;also are formed with'flatfwedge faces 28 for iengagementiwith..the :fl'atwedge surfaces it of thefollower wedges. .On' each side ;o'f"the shoe is gasgroovei. l9j'to which reference has vJbeen gmade, ,these. groovesbeing formed substantially parallel LWi-thfhe owedgetface '28.

LTheJfollower. wedge l3 fiisrshown .in detailxin Figs. ,hjan'ol 6.11 It. is generally rectangular in shape, .the opening H thereof being defined"by ithae'dgestof the wedges-surfaces 14 and the arcuatfiportions 2,9.whic'h are .formedtc clear the :shoulderediendr l fi to'f .itheffrictionstem. The pro jectionsr or lugs 18.. are; arranged substantially parallel with .the .wedgesurfaces Hi," their posiftion's. in relaltionltdthe grooves. I 9. being shown .in:Fi'gs.' 1 and 10;v on .the ltop and ibottoin' of the .wedge are .formed fnutwardly extending reinforc- .ing'sandtsupporting 'fiangesfSU'KFigs; 2; '5 and B) projecting outwardly from .the wedge .adiacent theacentnalopening 11.. These hanges'reinforce .the wedge adiacent the. opening L'L'and also pro ,vide abroad. supporting surfaces for enga ement with draftgear .supportslas lwill'be understood from Fig..2. V

t :-.The methodlof assembling thedraft gear is i1" .lustrated :in'Fig. .9; .-...'Ihe steps ,are as follows: The -.-f1fiotion stem .1 I .isplaced on end, on the a ssernbly bench and one of the follower wedge members 23 is..lowered intotplace against theback end ofthe -heaid 7910f. thestem. A ,pair ,of .thefric'tio'n' shoes lZTisen'tered into thewedge in a diagonal direcition, so that t the retainer ,lugs it of the wedge enter the igrooves lfi in the sidesof the shoes. After VtheJs'hoes are in position,"the spring i5 lowered onto" them. and a pair of spring corn- .ipressing clamps 3 I 'is.arranged to grip the spring near. its upper end and compress it almost to its @sonameight.

, Whilethespring is thus 'heldunder :compres- Lsion,-.the upper pair of friction shoes i 2 is placed .Jafetween the. spring and upper follower "member 13in the angular position shown in Fig: 9. The

The head of the friction stem it lies upper wedge is then lowered onto the shoes, the retainer lugs l8 on the wedge entering the grooves 19 in the shoes. The shoes are then tipped into position against friction stem 5 l, the retainer lugs I8 completely entering the grooves and the follower wedge finally seating on the shoes withthe wedge faces Jilin the engagement with the wedge faces 28'0f'thehoes. 'The spring clamps 3| are then removed, releasing the spring 'which forces the ends of the shoes into tight en- "gagement with the shouldered end It: of the stem.

In Fig. 10 the parts ,are shown approaching this positionas thereisremains a slight clearance at between the ends of the shoes and the shouldered end Jfi of the stem. Fig. 10 is a horizontal sectional view based on the position of the parts asdllustratediimli igs. 1 and 2 and thus shows the parts icompressed to an extent sufficient to fit the draft gear pocket between the lugs 2i and 22. However it will. be understood that when not so compressed the-upper pair of *shoes I zfwill-"o'ome up against the shouldered end 1'6"- of the *stem:

In that-positionwhe' friction stem; "shoes and.

'weolge areinterlockedand the 'wedge cannot *be removed For-replacement of fparts' the "spring can be compressed as illustrated in Fig,- 9, H r mitting disassenibly byreversing the order of assembly "described above The operation of i the assembled draft gear is as follows:v V V Under a ipullffloadthe "coupler :moves the-niction stem to "th'egle'ft-as viewed. in Figs." -1'-'and "2-; The firstmovemen't "takes up th'e'sm'all "amount of "clearance at b between' 'therend *o'fthe friction stem and' the rear "friction shoes "I 2. clearance"has been taken-"up; thefriction shoes are moved to the ileft'with the follower wedgeil 3 'and "compress 'the spring E5. The "forwardfrim tibri shoes 12' 'areheld 'stationary'ioy theforward wedge-1'3 abutting tl'ieforward draft lugs '21. This wedge thereforepresses"=th'e"forv. ard*shoes against thefriction-stem"andfrietion is" generated V as "the'*"fricti0n= "stem-:moves 'relatively" to thoseshoes. The -taper' of the "friction surfaces 26. of the stem force'sthe' frictionshoeslaterally During this "pullingxnrovement; the retaining .theigl'ooves "t9 inf'the'rear friction shoes," "serve to carry the 'rear wedge forward "with the shoes, thus "holdingiit in'proper position at all times;

In 'buffing. the .action is similar to "that'fin pull 'ing except that .the 'rear -friction shoes are't'the oneswhichzareheld sta'tionary and "the friction 'stemt'il'l moves :rearwardly in-relation to them. The preferred draft gear construetionwhichwe havede'scribe'd :is "intended primarily for "serv -ice. on) carsfintthe coal mineffield. In manyy'of these m'ihes'the cars are turned upside "downyone ior"two at a' 'tin1e,"without' uncoupling them from the "train; It is' "therefore necessary that the couplerl and with it the friction stemH to'whic'h' the coupler "is attached," shall -"be "able-"to" rotate around "a longitudinal axis: It is for "tIfis re'a *son that "we prefer to make the '-frictiontstem' of generally cylindrical shape so thatit can rotate wh'ilethe friction shoes and :we'dg'es remain 'sta 'tionary-relaltivete the carr Generally the edraft' gear will be applied only to one end of a car so asaapos '1 that its coupler will normally be coupled with a non-rotatable coupler of an adjacent car whereby, after a car has been turned upside down and returned, the couplers will return to the correct position for angling in a horizontal di-- rection. The head 2i] may be formed with flattened surfaces adjacent flanges 30 for engagement therewith to prevent rotation of stem II.

The terms, and expressions which we have employed are used in a descriptive and not a limiting sense, and we have no intention of excluding such equivalents of the invention described, or of portions thereof, as fall within the purview of the claims.

We claim:

l. A railway draft gear comprising a friction stem, friction shoes for engagement with the friction stem, a follower wedge for engagement with the friction shoes to wedge them against the friction stem, and spring means for opposing movement of the shoes along the friction stem, the friction stem having means for limit ing movement of the shoes in one direction, the follower wedge being constructed and arranged to pass over the end of the friction stein during assembly therewith, and the follower wedge and friction shoes having interlocking means which cooperate with said limiting means to hold the follower wedge in assembled relationship with the friction stem and friction shoes.

2. A railway draft gear comprising a friction stem, friction shoes for engagement with the friction stem, a follower wedge forengagement with the friction shoes to wedge them against the friction stem, and spring means for opposing movement of the shoes along the friction stem, the friction stem having means for limiting movement of the shoes in one direction. the follower wedge being constructed and arranged to pass over the end of the friction stem dur-- ing assembly therewith, and the follower wedge and friction shoes having interlocking portions arranged at an angle to the axis of the friction stem.

3. A railway draft gear comprising a friction stem, friction shoes for engagement with the friction stem, a follower wedge for engagement with the friction shoes to wedge them against the friction stem, and spring means for opposing movement of the shoes along the friction stem, the friction stem having means for limiting movement of the shoes in one direction, the follower wedge being constructed and arranged to pass over the end of the friction stem during assembly therewith, and the friction shoes having locking surfaces which, in the assembled position of the friction stem, wedge and shoes, engage portions of the follower wedge to hold it against removal.

4. A railway draft gear comprising a friction stem, friction shoes for engagement with the friction stem, a follower wedgefor engagement with the friction shoes to wedge them against the friction stem, and spring means for opposing movement of the shoes along the friction stem, the friction stem having means for limit-- ing movement of the shoes in .one direction, the follower wedge being constructed and arranged to pass over the end of the friction stem during assembly therewith, and the follower wedge and friction shoes having coacting projections and grooves constructed and arranged to slide into engagement as the follower wedge is passed over the end of the friction stem and to be retained in engagement by. coaction with the spring and aforesaid limiting means.

5. A railway draft gear comprising a friction stem, friction shoes for engagement with the friction stem, a follower wedge having inclined wedge surfaces for engagement with the friction shoes, and spring means for opposing movement of the shoes along the friction stem, the friction stem having a shouldered end for limiting movement of the shoes, the follower wedge having a central opening to clear the shouldered end of the friction stem during assembly therewith, and the follower wedge and friction shoes having coacting projections and grooves cooperating with the shouldered end of the friction stem to hold the follower wedge and shoes against removal.

1 6. A railway draft gear comprising a friction stem having substantially cylindrical friction surfaces, friction shoes having complementary friction surfaces for engagement with the friction surfaces of the stem, a follower wedge for engagement with the friction shoes, and spring means for opposing movement of the shoes along the friction stem, the friction stem having a shouldered end, the follower wedge having a central opening to clear the shouldered end of the friction stem during assembly therewith, flanges projecting outwardly from the follower wedge adjacent said central opening, and the follower wedge and friction shoes having interlocking projections and grooves.

'7. A railway draft gear comprising a friction stem having substantially cylindrical friction surfaces, friction shoes having complementary friction surfaces for engagement with the friction surfaces of the stem, a follower wedge for en gagement with the friction shoes, the follower wedge and friction shoes having coacting projections and grooves, and spring means for opposing movement of the shoes along the friction stem, the shoes having portions extending into the spring means, the friction stem having a shouldered end, the follower wedge having a central opening therethrough to clear the shouldered end of the friction stem during assembly therewith, and flanges projecting outwardly from the follower wedge adjacent said central opening.

8. A railway draft gear comprising a friction stem, two sets of friction shoes for engagement with opposite ends of the friction stem, a follower wedge for engagement with each set of friction shoes to wedge them against the friction stem, and a compression spring arranged between the two sets of friction shoes, the friction stem having a shouldered end, the follower wedge adjacent the shouldered end having a central opening to clear said shouldered end during assembly therewith, and the follower wedge and friction shoes adjacent the shouldered end having interlocking projections and grooves inclined to the axis of the friction stem for assembly of the wedge and shoes with the friction stem when the spring is compressed and for holding them against removal from the friction stem when the spring is released.

9. A railway draft gear comprising a friction stem, two sets of friction shoes for engagement with'opposite ends of the friction stem, a follower wedge for engagement with each set of friction shoes to wedge. them against the friction stem, and a compression spring arranged between the two sets of friction shoes, the friction stem having a shouldered end, the follower wedge adjacent the shouldered endhaving a central opening to clear said shouldered end during assembly therewith, and the follower wedge and friction shoes adjacent the shouldered end having intertozsurroundzportions oiiahe frictionshoes 1111A railway draft "gear comprising -a-ifrictionr rt-woisets of affiction shoes for iengagement x.

with: opposite ends :1 of "the @friction i-stem; 9.0;f01fi having a shouldered end, the followerswedges.

havingneutral openingsxto; clear saidcvshouldered endmzing'e'assemblywith heirictionsstemuand; 1:11 oi'l'owerwedgerandifiriction.vshoesxadgiacentr the-ush'oulderedrrend aving iinter lo cking;;pgojeo=: ti-ons fantdigro'oves inclined :tdthe axis ofithe iii-G151- With Z-bh'e p'i'ess'edsan or holding themag-ainstzsremoval from the fri'ctionstemrwhenathe spring is releasedi springt me: ffol'l'owerzwedgeaandz shoes having' icm acting projections and groovesxisaidigroovesibea 118:;lf1ii6tii0112 sstem Jon ,1 assembly-011m? wedgeandshoes withthe friction stem-whemthes spring; is? compressed; and for: holding: themagainst removal-Yfrom the irictionzstem when thee; spring ismreieased; the: spring being constructed;

845; ings-i-noli nedo to the axis oiihe .friction. stems-furs: angulannassemblya oi. the ifiotrionsshoes. to-bring L:

thea shoesaand wedge into interlocking spositlorr;

with hthe shoes inside. ..the. (enlarged .endjLof the V friotion stem,

12: a railway draft; gearw a: friction hayinggan' enlargedend, asiollowerflwedge having a central opening to: clear .said. enlarged end;v frictionshoes, and splcingmeans s-urroundimg por w tionsaof. the shoes dnwardiy A projecting .lu-gsiinsaidacentnal opening; and inclined grooves m the: motion shoeshit-engagement withisaid lugspth'eh.

engaging lugsia-nd grooves conjunction with.

the spring means maintaining the partshin assembled relation.

HUBERT L. SPENCE;

M MEEEZGERL;

" REFERENCES"CITED" I The'aiol lowingyreferencesare of..record;im the-- tnmirstem m'sassembly: of theawedgesand shoes-1a:

'UNITEDSTATES"PAIENTSY 7 Number; Name Date,

9444321vv French etial. ;Dec,v 2B,l19091 51,2513g7565 Newel-l 001123119171 115M987- i vShermanvetal. i Deo.11;1928i -1;8'97 ,730 Halli-- d Feb; 14,.1933 1 2 073361 Shafe'r-h VMar.'. 1611937.? 

